[Effect on beta adrenergic receptors of tachyphylaxis on the sensitivity of smooth muscle in the bronchi to beta adrenergic receptor agonists in bronchial asthma].

The study involved 30 subjects: 15 healthy individuals and 15 patients with atopic bronchial asthma of the moderate degree. Salbutamol was administered to asthmatic patients in the intravenous infusion for 7 days. beta-adrenergic receptor density in the lymphocytes and FEV1 were evaluated before and after therapy. Moreover, isoprenaline test was carried out to evaluate the sensitivity of the bronchial smooth muscle to beta-agonist. The test was performed prior to and after salbutamol therapy. It was found that beta-receptor agonist statistically significantly decreases beta-adrenergic receptor density. Equivalently, bronchial smooth muscle is less sensitive to beta-agonist in the same degree as a decrease in beta-adrenergic receptor density in the peripheral blood lymphocytes.